Understanding principles of fluid mechanics has enabled humankind to direct fluid (air, water, and other gas or liquid) flows and harness flow energies in a wide variety of circumstances. The Venturi effect in fluid dynamics occurs at a constriction of a lumen through which a fluid flows. Any fluid passing through the constriction experiences an increase in velocity, because fluid velocity is inversely related to the cross section of a lumen through which the fluid passes. So that mechanical energy is conserved when the fluid velocity and the corresponding kinetic energy are increased, potential energy and the corresponding fluid pressure decreases. Therefore, the Venturi effect refers to the increase of velocity and the accompanying decrease of pressure at a constriction in a pipe. The Venturi effect and other properties of fluid dynamics have been studied and exploited in a wide range of applications.